2. Write the regular expression for the following over {a,b) or (0,1} 1. Strings with exactly three occurrences of ba. 2. Strings with at most 3 occurrences of ba 3. L = {an bm|m+n is even} 4. Set of all the strings with exactly 2 a's over {a,b} 5. All the strings containing the substring ccc over the set {a,b,c} 6. set of all the strings when ever run of 'a' has a length of 4 over {a,b, c}.